Back to Basics - This is not the object you’re looking…wait, oh, it is the object

Scott Hanselman’s Computer Zen - Back to Basics - This is not the object you’re looking…wait, oh, it is the object

Know your options, but above all, know your intentions and make sure that the code you’re writing correctly expresses your intent.

Linq and RegExp

I’ve always struggeled with RegExp. Every time I need one I have to use a tool and then carefully create it. Painful. But today I discovered a new project: Readable Regular Expressions. I basically uses Linq syntax to create the regexp for you! Pretty cool!

Designing With Lambdas - Part I - Sergio Pereira

Pretty cool use of Lambdas. Passing functions around is really handy!

Designing With Lambdas - Part I - Sergio Pereira

Charlie Calvert’s Community Blog : Video of Luke Hoban’s In-Depth Look at C# 3.0

More of a bookmark than anything; I really wanna watch these two presentations asap.

Charlie Calvert’s Community Blog : Video of Luke Hoban’s In-Depth Look at C# 3.0

Double Key Dictionary

Double Key Dictionary, or; how to make it really simple to use a dictionary with two keys.

In a matter of just weeks I found myself forced to temporarily store values with two unique identifying keys. As an example think about a customer in a web shop who has bought some books. Key number one would be the customer ID and then key number two would be the books ISBN number. The value stored could be the books name. Why you would want to do this I have no idea, but it’s an easy to understand example and it illustrates the problem I had so that everybody can understand it. Its just that I read values from, literally, thousands of Xml logs stored in a database… Anyway!

So what you could do is something like this:

Dictionary<string, Dictionary<string, string>> bookList = new Dictionary<string, Dictionary<string, string>>();
Dictionary<string, string> innerList = new…
innerList.Add(”11-22-33″, “Lord of the Rings”);
bookList.Add(”James”, innerList);

That works and would perhaps be good enough. But what happens if you want to compare two lists of books? And it’s not unthinkable that you might end up trying to add the same book, for the same person, more than once. How do you handle that? Lots of manual checks? More on my solution later on…

Even if I could make the problems outlined above go away (as in create little helper methods to sort them out) I just didn’t like the syntax. It felt just so wrong. What I wanted would be something like this:

DoubleKeyDictionary<string, string, string> bookListEx = new DoubleKeyDictionary<string, string, string>();
bookListEx.Add(”James”, “11-22-33″, “Lord of …”);

(Abbreviated for clarity)

So I implemented the DoubleKeyDictionary, as a two key generic dictionary. My implementation also includes IEnumerable<T>, IEquatable<T> and I added an index. All this enables me to use this syntax:

DoubleKeyDictionary<string, string, string> bookListEx = new DoubleKeyDictionary<string, string, string>();
bookListEx.Add(”James”, “11-22-33″, “Lord of the Rings”);

DoubleKeyDictionary<string, string, string> bookList = new DoubleKeyDictionary<string, string, string>();
bookList.Add(”James”, “10-20-30″, “Narnia”);

if (bookList.Equals(bookListEx))
    Console.WriteLine(”They are equal”);

foreach (DoubleKeyPairValue<string, string, string> books in bookListEx)
    Console.WriteLine(books.ToString());

Sorry about the bad formatting. Please download the actual code file [new window]. Please feel free to use the code if you like it. If not; tell me why!

Joshua Flanagan - The power of yield (return)

yield is pretty cool and this was a simple and good example of how to use it and why you would want to. 

Link to Joshua Flanagan - The power of yield (return)

C# 4.0 Feature Request: "??=" the Lazy load operator… - The Bolla Blog

Not bad… I can see lots of uses for such an operator. However I do fear that we’re soon approaching “feature bloat” in C#… I worry alot about that actually… 

Link to C# 4.0 Feature Request: “??=” the Lazy load operator… - The Bolla Blog

J.D. Meier’s Blog : How To: Create a “Hello World” WCF Service Using Visual Studio

 

Link to J.D. Meier’s Blog : How To: Create a “Hello World” WCF Service Using Visual Studio

PaulStovell.NET » Introducing SyncLINQ

 

Link to PaulStovell.NET » Introducing SyncLINQ